The core of the idea would be flameproof cuffs with electrical ignitors in them.
The flames wouldn't have to be continuous, you could just squirt fuel into the air supply randomly for it to shoot out the arm holes in big fireballs.
A possible opponent to go up against AusCan531's sword fighting flailing man. If it got cut, it would "bleed" fire.-- doctorremulac3, Sep 20 2013 The same fluid mechanics at work here http://www.youtube....watch?v=gJ7HxzEvfJkNot a problem [doctorremulac3, Sep 21 2013] Melbourne Gas Brigades http://www.youtube....watch?v=4vnb25awS9QA titch safer that [drem3]'s idea - unless you happen to be a bird flying by. [AusCan531, Sep 21 2013] //Blow fuel/air mixture into the bottom//
I think I see a problem here. The problem involves words like propagation and explosion.-- MaxwellBuchanan, Sep 20 2013 Plastic tube and a hair dryer should allow you to prove you can control the flame. Don't test inside the building.
Wet face and hands before ignition so you might keep your eyebrows. Don't wet dryer. I wonder which plastic tubes support combustion and which simply melt?-- popbottle, Sep 20 2013 It's going to become increasingly hazardous just walking down the sidewalk past places of business.
"Our accountant informs me that the dramatic increase in customers is offset by our increased insurance premiums."-- normzone, Sep 20 2013 Oh yes. Get those hands really wet before you handle the hair dryer, [pop]. Have you considered a career in health and safety?-- MaxwellBuchanan, Sep 20 2013 //I think I see a problem here. The problem involves words like propagation and explosion.//
Not a problem. Keep the air flow high enough to keep the flame where you want it.
If you really want to play it safe just squirt the occasional blast of fuel to make it puff flames like a dragon.
And if the worst happens, you could just have the thing held together with breakaway, I don't know, velcro or something. It pops open, you zip it back together and start again. Might even want to end the show with a big bang by stopping the fan.-- doctorremulac3, Sep 20 2013 [+] I like the idea of a Wacky Waving Inflatable Arm Flailing Tube Man Flamethrower but, as is, it's a WWIAFTM Bomb.
//Keep the airflow high enough//
For a slightly less boring surf than Googling for "fuel air deflagration velocity", look in YouTube for "fuel/air bomb".
//Plastic tube and a hair dryer// oh, do tell.
Long story short, a near-stochiometric mixture of fuel and air will simply blow up right back to where the fuel enters the airstream, pretty well immediately following ignition at any point.-- FlyingToaster, Sep 21 2013 If the velocity of the propagation of the explosion is slower than the velocity of the blower you don't have a problem.
See link.-- doctorremulac3, Sep 21 2013 The gang is right about the risks of a stoichiometric air/fuel mix but the risk could be mitigated by delivering the gas to the ends of the cuffs with a flexible fuel line rather than injecting the gas with the air at the bottom of the man.
For a look at a roughly similar concept - albeit rigid tubes with no flailing involved - have a look at the Gas Brigade artwork on Melbourne's Southbank. Video link attached.-- AusCan531, Sep 21 2013 //you don't have a problem// oh well in that case I'll add a buck to 8th's standard offer for "video of me trying this". Remember to get a nice stochiometric air/fuel mixture in your lungs far in advance of the ignition point rather than, say, squirting fuel out between the two upper front teeth where vapourisation/mixture takes place a couple of centimeters away from the face.
Though there might be a couple of fringey ways of actually getting it to work the way you envision it: maybe providing a too-rich mixture with a gaseous fuel, like propane, and air.-- FlyingToaster, Sep 21 2013 //I think I see a problem here. The problem involves words like propagation and explosion.//
We think we see an opportunity here. The opportunity involves words like propagation and explosion.
Stoic fuel-air mixture [+]-- 8th of 7, Sep 21 2013 The fuel air mixture coming out of the crazy guy's mouth in the video does illustrate the ignition propagation speed < fuel/air mixture flow velocity concept. The flames don't reach back to his lips. The whole thing would have to be fireproof though. At some point you'd have to turn the air off and the fire would burn back through the whole unit that would now be coated with fuel. So the gas lines direct to the hands might be a better way to do it.
Unless the flames propagating back through the thing were a neat effect. You could just lean up the mixture enough to lessen the explosive impact on the envelope. Then you could have the whole thing light up, not just the flailing hands. So you'd shoot a blast of fuel/air mix into the stream, when it hits the arm hole ignitors you get the balls of flame that then shoot down through the thing lighting it up. Make it flexible so it would puff up and not get ripped to apart by the explosion. Propane would be the thing to use.
Ok, so here's the design:
Propane shot into the thing in blasts, not continuous.
Ignitors at the arm holes.
Make it flexible enough to expand and vent the explosion. Venting flaps could also be sewn throughout. Stiff enough to stay closed when the air is flowing but would open when the propane exploded dissipating the explosive force.
Make it somewhat translucent so the flames coming back through the unit would be visible.-- doctorremulac3, Sep 21 2013 For that matter, if you're able to explosion-proof this thing, why bother with the armhole ignitors? Just shoot a ball of burning propane in at the base have it fly up through the whole envelope and out the arm holes. You'd get a Stay Puff Marshmallow man effect. Sell the idea to an antacid maker for a commercial. "Did that bowl of chili make you feel like this?" They might want to re-locate the vent hole to get the idea across better.
I don't think you'd have to fireproof it since the flames wouldn't linger on the material long enough to set it on fire. You could also atomize water into the air stream between propane squirts if necessary.-- doctorremulac3, Sep 21 2013 Just make it out of Nomex. As the doc says, if it's properly vented the material will never get hot enough to incur damage.-- Alterother, Sep 21 2013 random, halfbakery